1. Field of the Invention
The present invention relates to a tube-in-tube heat exchange system and, more particularly, to a coaxial multiple-tube system in which heat exchange between the fluids in the system is by means principally of a metal-to-metal thermal path.
2. Description of the Prior Art
The prior art shows a number of examples of tube-in-tube heat exchange systems such as the designs of L. Meyer et al. and R. H. Carter in U.S. Pat. Nos. 2,316,273 and 2,847,193, respectively, and the designs disclosed in British Pat. No. 1,145,513. Although the first two references do not incorporate leak detecting means in their systems, such means are taught in the latter reference. The prior art discloses that it is also known to incorporate leak detecting means in tube-in-shell type heat exchange systems. Such designs are disclosed by E. Thamasett et al. in U.S. Pat. No. 3,830,290 and by G. A. Plummer in British Pat. No. 804,592.
Inasmuch, however, as none of the prior art heat exchangers provide radially inwardly projecting integral fins on each of the coaxial tubular members comprising their heat exchange means as is the case in the present invention, it is seen that their efficiency suffers thereby and the metal-to-metal heat path of this invention is a novel improvement over the prior art.